Corpuscular ray microscope with means to insert specimen chambers of various sizes in the column thereof

ABSTRACT

A specimen chamber exchange device in a corpuscular ray microscope having a microscope column with a top portion, specimen chamber and a lower portion. A lifting mechanism raises the top portion a rectilinear distance above the lower portion sufficient to accommodate the highest specimen chamber to be used with the microscope. Upon reaching this elevation, a continued actuation of a drive means causes the top portion to follow a curvilinear upward path which moves it laterally away from the column axis thereby rendering the specimen chamber accessible from above. The top portion can be positioned to accommodate any of several chambers having different heights.

United States Patent Inventor Ekkehard Fuchs Munich, Germany Appl. No. 530.055 Filed Feb. 25, 1966 Patented June 22, 1971 Assignee Siemens & Halske Aktiengesellschaft Berlin, Germany Priority Mar. 2, 1965 Germany 95,735

CORPUSCULAR RAY MICROSCOPE WITH MEANS TO INSERT SPECIMEN CHAMBERS OF VARIOUS SIZES IN THE COLUMN THEREOF 3 Claims, 2 Drawing Figs.

US. Cl 250/495 Int. Cl H01j7l26 FieldofSearch vISO/495th. 49.5(2), 49.5(4) 49.5 1 350/845, 87; 74/89, 99, 22,567, 569

References Cited UNITED STATES PATENTS 2,953,344 9/1960 Yancey 74/89 4/196] Malfeld 350/87 3,316,402 4/1967 Schmidt et al. 1. 250/495 (4) 2,256,191 9/1941 Borries et al..,.. 250/495 2,370,373 2/1945 Ruska et al.. 250/495 FOREIGN PATENTS 1,195,520 2/1962 Germany 250/495 (2) Primary Examiner-James W. Lawrence Assistant Examiner-C. E. Church Attorney-Curt M. Avery ABSTRACT: A specimen chamber exchange device in a corpuscular ray microscope having a microscope column with a top portion, specimen chamber and a lower portion. A lifting mechanism raises the top portion a rectilinear distance above the lower portion sufficient to accommodate the highest specimen chamber to be used with the microscope. Upon reaching this elevation, a continued actuation of a drive means causes the top portion to follow a curvilinear upward path which moves it laterally away from the column axis thereby rendering the specimen chamber accessible from above. The top portion can be positioned to accommodate any of several chambers having different heights.

PATENIEuJuuzzlsn 3586.855

Fig.2 ls/bi CORPUSCUILAR RAY MICROSCOPE WITH MEANS TO HNSERT SPECIMEN CHAMBERS OF VARIOUS SIZES IN THE COLUMN THEREOF My invention relates to corpuscular ray microscopes, particularly electron microscopes.

As a rule, the microscope column of such apparatus comprises a top portion, containing the ray generating system and the condenser lens, which can be removed from the specimen chamber portion of the column by means of a lifting device which permits raising the top portion and then swinging it laterally away from the specimen chamber. The raising travel is in the direction of the microscope ray axis, where as the swinging motion is in a plane transverse to the axis.

Generally, a lifting travel of no more than about 2 cm. is sufficient for the upper portion to reach a position in which it can be freely swung away to permit removing the columnar portion containing the specimen chamber. In modern investigation techniques, such as research relating to ferromagnetic materials, it has been found desirable to observe the specimens under defined external influences which cause changes in the specimen. These techniques make it necessary to keep the specimen chamber more readily accessible, such as for introducing coils for heating the specimen or producing defined magnetic fields, or for introducing stress producing devices and the like. This leads to providing a larger specimen accommodating space than needed for the conventional investigation techniques, particularly a specimen chamber of greater axial height than that of the conventional specimen chambers.

This requirement, in principle, could be satisfied by providing the microscopes from the outset with higher specimen chambers. This would involve the necessity of correspondingly dimensioning the device for raising the top portion of the microscope column with the ray generating system and the condenser; but aside from such dimensional change, a lifting device of conventional type can be employed for a microscope equipped with a specimen chamber of increased height.

On the other hand, it is frequently necessary to operate a corpuscular ray microscope with an extremely small diameter of the corpuscular ray at the specimen; and such a small diameter can be realized only with the smallest possible distance between the focusing condenser and the specimen; and the known microscopes do not permit readily changing between fine focus operation and investigations calling for additional coils or other auxiliary equipment in the specimen chamber.

It is an object of my invention to facilitate such a selective operation.

Another object of the invention is to permit an exchange of differently high specimen chambers in an electron microscope or other corpuscular ray microscope while retaining the well proven construction of the lifting device for raising the upper portion in the abovedescribed manner.

In accordance with my invention, 1 provide the microscope column of a corpuscular-ray microscope with several specimen-chamber portions of respectively different heights which are selectively insertable into the column; and I give the device for raising the top portion of the microscope column in the direction of the microscope axis such a design that the top portion, regardless of the selected specimen chamber, is always lifted to the position required for insertion of the highest specimen chamber, before the device commences to swing the top portion away from the microscope axis.

In principle, therefore, my invention provides for compensation between the different heights of the various specimen chambers by correspondingly different clearances between the fixed fully raised position of the lifting device and the top of the particular specimen chamber portion located in the microscope column.

Preferably the lifting device is dimensioned for a lifting travel of about 6 to 10 cm. This, as a rule, covers the largest difference in height between the specimen chambers required for the various investigations.

There are several ways of making the lifting type device suitable for operation 'with specimen chambers of different heights. For example, the abutment or supporting point of the crane device may be shifted in accordance with the particular height of the specimen chamber portion inserted into the microscope column. This, however, results in the necessity of fundamentally changing the construction of the equipment; and such considerable change can be avoided by designing the device in the manner described presently with reference to the accompanying drawing in which:

FIG. 1 shows schematically and partly in section a microscope column with a device according to the invention; and

FIG. 2 shows separately two specimen chamber portions, one in front of the other, having respective axial heights different from that of the chamber portion illustratedin FIG. 1.

The illustrated apparatus comprises a vertical rod 1 whose upper end carries a laterally protruding holder 2 which is bifurcated to freely straddle the specimen chamber portion 5 of the microscope column beneath the top portion 3 of the column containing the ray generating system and the condenser lens system. The microscope column 4 further comprises a portion 6, which contains the objective lens system, and a nonillustrated bottom portion with the further image producing lenses, such as the projection lens and in some cases an intermediate lens, as well as the tubular end portion in which the ultimate image is formed.

The bottom end of the vertical rod 1 is provided with a screw thread 7 which engages an interiorly threaded sleeve 8. The sleeve 8 is rotatably mounted and can be placed in rotation about its axis with the aid of a conical gear transmission 9 and a hand crank 10. When the crank is being actuated, the rotary motion imparted to the sleeve 8 causes the threaded end 7 to be gradually raised. The upward motion of the rod 1 thus produced is constrainedly guided by a cam mechanism which comprises a fixed cam sleeve 13 in which the rod 1 is vertically displaceable and which has a cam slot 12 whose lower portion 11 extends straight upwardly and whose top portion curves laterally as shown at 16. A cam follower pin 14 protruding from the rod 1 engages the slot 12. The vertical portion ll of the cam slot 12 is slightly longer than the height of the highest specimen chamber portion to be inserted into the microscope. Operation of the crank 10, therefore, has the effect that the top portion 3 of the microscope column is always lifted to the position required for inserting the highest specimen chamber portion, regardless of whether this particular chamber portion or a lower chamber portion is inserted. For example, the vertical length of the slot portion 11 is 6 to 10 cm., although a greater length of the slot must be chosen in cases where a still higher specimen chamber is required.

In the illustrated example the height of the straight portion 11 of the cam slot corresponds to the height of the specimen chamber portion 5b, this height being larger than that of the specimen chamber portion 5 inserted into the microscope column. The same microscope is provided with a lower specimen chamber portion 5a.

Upon completion of the straight lifting movement, the follower pin 14 enters into the curved top portion 16 of the slot 12. This cam portion now forces the rod 1, during continuing turning of the crank 10, to rotate about the rod axis, while swinging the top portion 3 of the microscope column away from the column axis 15 so that the specimen chamber portion 5 becomes accessible from above and can be lifted off portion 6 of the column.

The top portion 3 of the microscope column is shown connected by a corrugated and flexible conduit 17 to a vacuum pump (not shown), the flexibility of the conduit permitting the above-mentioned vertical and lateral displacement of top portion 3.

To those skilled in the art it will be obvious upon a study of this disclosure that the invention is not limited to the particular design of the cam mechanism or conical spur gear transmission shown but may be modified in various respects without departing from the essential features of the invention and within the scope ofthe claims annexed hereto.

lclaim:

1. In a corpuscular ray microscope comprising a microscope column having a top portion containing a ray generating system, a specimen chamber portion beneath and adjacent said top portion, a lower portion beneath and adjacent said specimen chamber portion, and a lifting device for removing said top portion from said specimen chamber portion and said lower portion by raising said top portion from said specimen chamber portion and swinging it away therefrom transversely of the column axis, the improvement according to which said microscope comprises a plurality of specimen chamber portions of respectively different axial heights selectively insertable into said column between said top portion and said lower portion, and said lifting device comprises a holder structure having a laterally extending holding portion which surrounds the specimen chamber adjacent to said top portion for holding said top portion of said microscope column, said holder structure also having a downwardly extending threaded rod member, and having a follower pin radially protruding from said rod member, a fixed sleeve traversed by said rod member and having a cam slot engaged by said follower pin, said cam slot having a straight lower portion extending upwardly a distance corresponding to the length of travel of the lifting device, and said cam slot having an upper portion curved laterally away from said straight portion to permit turning of said holder structure, an internally threaded sleeve rotatable about its axis and in threaded engagement with an end of said rod member and drive means for rotating said sleeve, said lifting devices Having a given axially upward travel preceding the transverse swinging motion, said upward travel extending up to a given height independent of the height of the selected specimen chamber portion and sufficient for insertion of the highest one of said specimen chamber portions.

2. In a corpuscular ray microscope according to claim 1, the maximum length of said upward travel being about 6 to ID cm.

3. In a corpuscular ray microscope according to claim 1, said lifting device comprising a cam member having a straight cam portion extending up to said given height and having a curved portion extending transversely away from said straight portion beginning at said given height, a follower member in engagement with said cam member, means connecting one of said two members to said top portion of said microscope column, and drive means connected with said other member for actuating said lifting device.

23 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent; No. 3,586,855 Dated June 22, 1971 Inventofls) EKKEHARD HS It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Priority number should read:

Signed and sealed this 2nd day of November 1 971 (SEAL) Attest:

EDWARD M .FLETCHER JR ROBERT GO TTSCHALK Acting Commissioner of Patents Attesting Officer 

1. In a corpuscular ray microscope comprising a microscope column having a top portion containing a ray generating system, a specimen chamber portion beneath and adjacent said top portion, a lower portion beneath and adjacent said specimen chamber portion, and a lifting device for removing said top portion from said specimen chamber portion and said lower portion by raising said top portion from said specimen chamber portion and swinging it away therefrom transversely of the column axis, the improvement according to which said microscope comprises a plurality of specimen chamber portions of respectively different axial heights selectively insertable into said column between said top portion and said lower portion, and said lifting device ''''comprises a holder structure having a laterally extending holding portion which surrounds the specimen chamber adjacent to said top portion for holding said top portion of said microscope column, said holder structure also having a downwardly extending threaded rod member, and having a follower pin radially protruding from said rod member, a fixed sleeve traversed by said rod member and having a cam slot engaged by said follower pin, said cam slot having a straight lower portion extending upwardly a distance corresponding to the length of travel of the lifting device, and said cam slot having an upper portion curved laterally away from said straight portion to permit turning of said holder structure, an internally threaded sleeve rotatable about its axis and in threaded engagement with an end of said rod member and drive means for rotating said sleeve, said lifting device.'''' Having a given axially upward travel preceding the transverse swinging motion, said upward travel extending up to a given height independent of the height of the selected specimen chamber portion and sufficient for insertion of the highest one of said specimen chamber portions.
 2. In a corpuscular ray microscope according to claim 1, the maximum length of said upward travel being about 6 to 10 cm.
 3. In a corpuscular ray microscope according to claim 1, said lifting device comprising a cam member having a straight cam portion extending up to said given height and having a curved portion extending transversely away from said straight portion beginning at said given heiGht, a follower member in engagement with said cam member, means connecting one of said two members to said top portion of said microscope column, and drive means connected with said other member for actuating said lifting device. 